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author | Xing Zheng <zhengxing@rock-chips.com> | 2015-11-05 15:33:55 +0800 |
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committer | Heiko Stuebner <heiko@sntech.de> | 2015-11-23 21:25:08 +0100 |
commit | 708e5ca4eb6bab0b023872f5e81fdbf8dd6342cb (patch) | |
tree | 8f711dd995465941497f58fb3f99f221e11c1f62 /Documentation/devicetree/bindings/clock | |
parent | 751be8f2eede261f9b3f7dc0dc80644b2b1893c6 (diff) | |
download | op-kernel-dev-708e5ca4eb6bab0b023872f5e81fdbf8dd6342cb.zip op-kernel-dev-708e5ca4eb6bab0b023872f5e81fdbf8dd6342cb.tar.gz |
dt-bindings: add documentation of rk3036 clock controller
Add the devicetree binding for the cru on the rk3036 which quite similar
structured as previous clock controllers.
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Diffstat (limited to 'Documentation/devicetree/bindings/clock')
-rw-r--r-- | Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt new file mode 100644 index 0000000..ace0599 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt @@ -0,0 +1,56 @@ +* Rockchip RK3036 Clock and Reset Unit + +The RK3036 clock controller generates and supplies clock to various +controllers within the SoC and also implements a reset controller for SoC +peripherals. + +Required Properties: + +- compatible: should be "rockchip,rk3036-cru" +- reg: physical base address of the controller and length of memory mapped + region. +- #clock-cells: should be 1. +- #reset-cells: should be 1. + +Optional Properties: + +- rockchip,grf: phandle to the syscon managing the "general register files" + If missing pll rates are not changeable, due to the missing pll lock status. + +Each clock is assigned an identifier and client nodes can use this identifier +to specify the clock which they consume. All available clocks are defined as +preprocessor macros in the dt-bindings/clock/rk3036-cru.h headers and can be +used in device tree sources. Similar macros exist for the reset sources in +these files. + +External clocks: + +There are several clocks that are generated outside the SoC. It is expected +that they are defined using standard clock bindings with following +clock-output-names: + - "xin24m" - crystal input - required, + - "ext_i2s" - external I2S clock - optional, + - "ext_gmac" - external GMAC clock - optional + +Example: Clock controller node: + + cru: cru@20000000 { + compatible = "rockchip,rk3036-cru"; + reg = <0x20000000 0x1000>; + rockchip,grf = <&grf>; + + #clock-cells = <1>; + #reset-cells = <1>; + }; + +Example: UART controller node that consumes the clock generated by the clock + controller: + + uart0: serial@20060000 { + compatible = "snps,dw-apb-uart"; + reg = <0x20060000 0x100>; + interrupts = <GIC_SPI 20 IRQ_TYPE_LEVEL_HIGH>; + reg-shift = <2>; + reg-io-width = <4>; + clocks = <&cru SCLK_UART0>; + }; |